Hitherto, 1,1,2-trichloro-1,2,2-trifluoroethane (hereinafter referred to as "CFC-113") is widely used alone or in mixtures with other organic solvents, preferably azeotropic mixtures, as solvents, washing and cleaning agents, heat transfer media, pressure transfer media, or insulating media, because CFC-113 has various advantages such as incombustibility, low toxity and selective solubility power that it can dissolve fats, greases, waxes and the like without erosion of metals and high molecular compounds like rubbers and plastics.
Recently, there has been rising troubles that chlorofluoroethane compounds like CFC-113 in which all hydrogen atoms are substituted by chlorine atoms and fluorine atoms (hereinafter referred to as "perhaloethanes") produce global atomospheric pollutions, that is, the perhaloethanes destroy the ozone layer encircling the earth. Accordingly, the use of the perhaloethanes must be quickly reduced.
For reducing an amount of the perhaloethane there is proposed a method of using mixed solvents of CFC-113 with organic solvents other than the perhaloethanes. According to the mixed solvents, however, an amount of the perhaloethanes cannot be reduced beyond a give amount because of lowering their performance, particularly lowering their selective solubility power. In addition, when using as solvents, the mixed solvents should have important properties such that the liquid composition can be easily controlled and that the used solvents can be easily collected and recycled. Also the mixed solvents are desired to use in vapor washing method. Though azeotropic mixtures satisfy the above requirements, it is very difficult to find such azeotropic mixtures. Accordingly, the development of new solvents is limited from this viewpoint, and thus there has been found no practically usable solvent which can be used instead of the perhaloethanes.
There have been researched various solvents which do not contain the perhaloethanes. However, from this approach an effective solvent cannot be found.
An object of the present invention is to provide solvents comprising HCFC-234, especially consisting essentially of HCFC-234 which has a good wax cleaning property, incombustibility, low toxity and chemical stability equal to or more than those of CFC-113, and has a selective solubility power to dissolve and remove stains such as waxes without erosion of plastics, rubbers and metals, and further may not destroy the ozone layer in comparison with CFC-113.
Another object of the present invention is to provide azeotropic solvent compositions comprising HCFC-234 and an alcohol which do not contain CFC-113 and have an enhanced solubility power to fluxes in comparison with CFC-113 in addition to the above effects of HCFC-234.
An object of the present invention is to provide azeotropic solvent compositions comprising HCFC-234 and cyclohexane which do not contain CFC-113 and can sufficiently remove paints and printing inks more than CFC-113 in addition to the above effects of HCFC-234.